Search

OBJECTIVE: : To explore the association between napping status and depressive symptoms in urban residents during the coronavirus disease 2019 (COVID-19) epidemic. METHODS: : The survey was embedded in the Wellness Living Laboratory-China (WELL China) cohort study. Health and lifestyle information during the COVID-19 epidemic were obtained via the telephone interview from April 8, 2020 to May 29, 2020. A total of 3075 residents aged 18 to 80 years from Gongshu district of Hangzhou city with complete data were included in the analyses. The World Health Organization-Five Well-being Index (WHO-5) was used to measure depressive symptoms. Multiple logistic regression model was used to assess the association between napping status and depressive symptoms in the participants. RESULTS: : The prevalence of depressive symptoms was 20.6% in the participants during the COVID-19 epidemic. Daytime napping behavior, especially napping time ≤30 min, was associated with a lower risk of prevalent depressive symptoms ( OR=0.61, 95% CI: 0.47–0.79, P

A method of the determination of the carbon-centred radicals in mainstream cigarette smoke using a spin-labelled fluorophore, 4-((9-acridinecarbonyl) amino)-2,2,6,6-tetramethylpiperidin-1-oxyl (TEMPO-9-AC), as a fluorescent probe is presented. After being producted by smoking in International Organization for Standardization (ISO) mode, the carbon-centred radicals in mainstream cigarette smoke were trapped by TEMPO-9-AC, a carbon-centred radical probe with a low fluorescence intensity. Then the latter was transformed to a stable diamagnetic o-alkoxyamine, a high-fluorescence compound. Finally, high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was used to demonstrate the structures of the carbon-centred radicals, and high performance liquid chromatography with a fluorescence detector (HPLC-FLD) was used to determine the concentration of the carbon-centred radicals. The results showed that the 10 carbon-centred radicals were detected in the mainstream cigarette smoke, and the total carbon-centred radicals concentrations for 1R5F, 3R4F, CM6, and two Virginia type cigarettes, were 52.5 nmol/cig, 214.6 nmol/cig, 424.1 nmol/cig, 68.6 nmol/cig, and 334.2 nmol/cig, respectively; and there was positive relation between the concentrations of the total amount of carbon-centred radicals and the tar amounts in the mainstream cigarette smoke. The detection limit was 0.318 nmol/cig, and the relative standard deviations (RSDs) ranged from 3.5% to 9.7%. This method is suitable for the determination of the carbon-centred radicals in the mainstream cigarette smoke.

With a combination of QuEChERS method and gas chromatography-tandem mass spectrometry (GC-MS/MS) technique, three sample treatment methods (solvent exchange method, toluene dilution method, hexane liquid-liquid extraction method) were established to analyse more than one hundred pesticide residues in tobacco. The 155 pesticide analytes contained 58 organophosphorus, 28 organochlorine, 10 pyrethroids, 10 acyl amide, 11 carbamate, 7 dinitroaniline and 31 other family pesticides. Comparison of the three treatment methods was investigated on performances including matrix effect, co-extracted matrix, peak interference, recovery and the limit of quantification (LOQ). The hexane liquid-liquid extraction method gave the cleanest extract but poorer recovery; the solvent exchange and toluene dilution method could guarantee recoveries in the range of 70% and 120% for most of the 155 pesticides. We found that organophosphorus, acyl amide and carbamate pesticides exhibited relative strong matrix effects compared with organochlorine and pyrethroid pesticides. Toluene dilution method was recommended to analyse organophosphorus pesticides, and hexane liquid-liquid extraction (LLE) method was recommended to analyse organochlorine and pyrethroid pesticides.

In this paper,the optimum temperature,salinity and pH for juvenile growth of Ruditapes philippinarum were determined through the response surface methodology(RSM).The multivariate non-linear model was applied to study the interactions and optimization of the growth parameters for R.philippinarum which were explored by experiments.The results showed that:(1)there were significantly positive correlations between growth of shell length and temperature and salinity within the range of experiment design.The relationship between growth of shell length and temperature and salinity and the growth of shell-length verged to positive correlation,and the calm grew better between pH 8 and 9;(2)there were no significant interactions between temperature,salinity and pH for the growth of juveniles.The multivariate non-linear model is as follows:Y=4.08+0.10A+0.18B+0.11C-0.055A2-0.13B2-0.12C2(R2=0.977 4),the optimum conditions for germination are as follows:temperature 29.65 ℃ and salinity 23.35‰ and pH=8.46±0.09.The experimental results indicated that the proposed model is reasonably accurate and can be used for describing and predicting the growth features of R.philippinarum in different environmental factors.